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bemelee

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Is a DVD ISO file equivalent to a DVD?

I plan to back up dozens of DVDs to an external hard drive connected to my laptop by using DVD Decrypter 3.5.1.0 to create ISO images. Before I buy the external 200 GB hard drive, I want to make sure my idea is going to work. I've tested DVD Decrypter on my computer by saving several DVDs as ISOs to my local hard drive and I can play them back fine (using Virtual DAEMON Manager V3.47 to make the ISO a virtual DVD drive and then playing it with a standard DVD software player).

I'm pretty sure I'll be able to burn the ISOs to the external hard drive and watch the DVDs on my laptop. However, to plan for the future I also want to be sure that later I'll be able to do whatever I want with this ISOs. In particular, I want to know if in a few years I should be able to burn them to DL DVDs that will play in most/all standard DVD players (once the price of DL DVDs comes down), use programs such as DVD Shrink to put them on CD-Rs, put them on a MythTV box, or basically do anything I could do if I had the original DVD. In other words, is the ISO created by DVD Decrypter equivalent to having the DVD itself? I assume that my computer can't even tell the difference between the ISO and the DVD (if I use the Virtual DAEMON Manager).

Please don't respond with "Yeah, that should work." I already know it probably should work. I want to know that it WILL work. I know some of you are real experts, so if you say it will, I'll believe you, but I'd also appreciate any links you can provide as a reference.

The only barriers I see are that somehow the decoding to an ISO changes it in a way that I can't get it back onto a DL DVD in a way that will play on most players, or that there is a strong expectations that software to do this will no longer be available in a few years for legal reasons. Any recommendations on particular settings I need to use for DVD Decrypter to make sure this is going to work? (I'm currently using settings such as "Remove Macrovision Protection" and removing all other types of protections (IFO/BUP).) I really really don't want to spend months saving all these DVDs as ISOs only to find out later that I can't use the ISOs because I somehow saved them wrong due to the fact that I didn't remove a protection (or removed one that I shouldn't have).

Thanks in advance!
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jmanGJHS97

Well, you and I both know that DVD-R technology is relatively new, so there are a few issues.  First, it's not really been decided whether the industry is moving toward +R or -R, so that will affect how you encode the files.  You can find burners that do both, but the issue is, if all the players move toward one or the other, you might have several images that are the wrong type.  It's clearly not advised to make a +R and a -R image of the same dvd either.

If you figure an average DVD holds 4.5GB of data, you'll only get 40 or so of them on the drive, so "dozens" might not fit.  Also, DVD-R media is getting cheaper by the day, so it might not be a bad idea to write these to another DVD, rather than spending a ton of money on the big hard drive.  It's not likely that DVD players will cease to play the recorded disks, and I don't know how often you'll want to watch 2 movies at once, so changing disks shouldn't be a big issue.

Also, will you not have access to the original DVDs in the future?  You could wait to see where the industry goes, and then do all your encoding later, rather than doing it now and guessing.

I'm not a DVD Decrypter expert, but I've used it a couple times.  It seems to work fine for most everything.  The key step would be creating the iso correctly.  From what I recall, DVD Decrypter only extracts the vob files, not turn them into an iso image, so you'll have to make sure the iso is how you want it, and I've not done much of that, so I can't give you any advice on that step.

Anyway, that's my 2 cents worth.

Jeff
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ASKER

Jeff, thanks for all the good info. I will not have access to the original DVDs in the future, so I need to make the copies now. You are correct -- I will only be able to fit, at the very most, approx. 40 DVDs on the hard disk. It seems to me though that the hard disk is cheaper, at about $1/GB, while blank DL DVDs are about $2/GB (plus having to buy a DVD burner, which I don't currently have). I prefer not to split the DVDs onto two DVD-R or DVD+R discs or use DVD Shrink because I want a perfect copy. Also, it seems that there is the occasional bad burn or scratched disk when creating DVDs, which is entirely avoided with a hard disk. In a few years, when DL DVDs cost about $1/disk and bad burns are far less frequent, then I'll burn the ISOs back onto DVDs to free up my hard disk for something else.

I was hoping that an ISO image is a perfect copy, so the root of my question is whether the ISO created by DVD Decrypter is, for all intensive purposes, as good as having the original DVD. Are you saying that when an ISO is created it is "encoded" as either DVD-R or DVD+R? (I had assumed that the ISO was independent of that.)

Thanks!
No, the iso itself is as close to perfect as you can hope to get.  You are correct there.  It's just like an iso of a CD, and it's up to your DVD burning software to know that it's a DVD instead.  I believe the +R or -R comes in when you try to burn the iso to the DVD, but I'm not entirely sure.  There may be a size limit to an iso file as well, but you can check into that.  As far as I know, I'd say your safe with putting the iso images on your hard drive for future use.

Jeff
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ASKER

Jeff, thanks again for the reply. Is there any more concrete evidence I can get that I'll be able to use the ISO in a few years in essentially any way I could use the original DVD?

I increased the points to 400.
A few years ago no one knew about DVD's, how can we predict what will be here in a few years?

History shows that there are 2 proven archival media, paper and stone. Nothing else is good enough. That said If you do put the images to your HDD you will need to have a backup of your HDD. Maybe tape will do.

There is recent evidance that recordable optical media suffers degridation and may become unreadable in as little as 1 year!

My best thought is that if you have the original DVD's then you could make a copy to use, and keep the original safe, until your copy fails then simply re-record it.

If yo don't have the original DVD's then your question is against EE ruls and we can't help you.

acmp<><
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ASKER

acmp, I will have the original DVDs, but they won't be exactly the same as the backup ISO, and in this particular case I do not believe it is against EE rules or the law. To make a long story short, I plan to buy the original DVDs and then save a "backup" content edited (family-friendly: removing swearing, extreme violence, nudity, etc.) version of the DVD as an ISO. Therefore I always have the original (un-edited) purchased DVD which is never used after the inital editing and is stored away in a box permanently, and one edited ISO (or possibly DL DVD in the future when prices come down) which is the only copy used. My understanding is that making one backup (edited or not) of the original DVD for personal use is permissible by law. Obviously, once I make the edited ISO, I want to be able to save it forever so I don't have to redo the edited version. (See CleanFilms(.com) and MovieMask(.com) for examples of way to get edited versions of an original DVD. And CleanFilms legally does exactly what I've described: saves one edited copy per original DVD, providing a NetFlix-type service with the edited copy.)

Now will you help me determine if an ISO is sufficient? I appreciate your help!
An iso image is the closest thing you'll ever get to having a digital duplicate of a dvd disk.  If you can keep the integrity of the iso intact, there's no reason you can't burn it to a dvd later.  This would mean backing up your 200GB HD to make sure the disk doesn't die on you.

It's impossible to know what the industry is going to do in 2 years, much less "in a few years".  That's a crap shoot, and you just have to make your best guess.  If you can get the iso in a form that doesn't have any decryption on it, you'll be good to go, assuming the industry doesn't implement some sort of new encoding and require it for a disk to play, but you can't predict something like that.

Here's some tutorials on DVD Decrypter, in case it helps:

http://www.nerddotcom.com/copy-dvd/backup-dvd.php

http://forums.afterdawn.com/thread_view.cfm/108483

Jeff
If your ISO is at the same datarate and compression as the original it is the same, the joy of digital media.

If you compress/shrink the film then it is not the same, though it may not show any perceptable loss of quality.

I have no experiance with editing DVD's to make them 'family friendly' but I have used DVD shrink to backup/ reauthor my DVD's. I only have a DVD5 burner (single layer) and most DVD's need to be 'shrunk' to fit. This does reduce the quality, but on most files I cannot tell the difference.

DVD Shrink supports DVD9 disks (dual layer) and should produce a perfect copy of any 'retail' DVD9 movie.

DVD Shrink is freeware

Hope this helps.

acmp<><
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ASKER

feff: "An iso image is the closest thing you'll ever get to having a digital duplicate of a dvd disk."

Closest thing? Is it not an exact digital copy, bit for bit?

acmp: "If your ISO is at the same datarate and compression as the original it is the same"

How do I make sure it is the same "datarate" and "compression." When I create the ISO, I don't make and settings for datarate or compression, so I assume it is the same datarate and is uncompressed.

My primary concern is that somehow the DVD decryption that might be used by DVD Decryptor, or the removal of region encoding that may occur in the creation of an ISO somehow will prevent me from burning the ISO to a DL DVD in the future in a format that is usable. Before I start going through all the work of creating edited ISOs, is there something I need to know about how I should configure settings in DVD Decrypter? (Yes, I've read the online tutorials, but I don't see specific mention of potential issues involved in burning and ISO to DL DVD, which may mean there are no issues.)
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acmp
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Thanks Jeff and acmp. I wish I could get a concrete reference to the fact that an ISO is an exact copy (except for removing the encoding), but your opinions make me feel more assured. Splitting the points.
Thanks, and good luck.